src/mjacob/annotations/memoized.py

   1 # This Python file uses the following encoding: utf-8
   2 '''
   3 Created on May 12, 2011
   4
   5 a simple memoization routine
   6
   7 @author: mjacob
   8 '''
   9
  10 def Memoize(func):
  11     """replace an function without arguments with a function that merely returns the result"""
  12     def f1(selv):
  13         value = func(selv)
  14         def f2():
  15             return value
  16         setattr(selv, func.__name__, f2)
  17         return value
  18     return f1
  19
  20 if __name__ == "__main__":
  21     """test functionality"""
  22     class foobar(object):
  23         def __init__(self, v):
  24             self.__v = v
  25
  26         @Memoize
  27         def thing(self):
  28             print("computing %s" % (self.__v))
  29             return 100*self.__v
  30
  31     a = foobar(1)
  32     b = foobar(2)
  33     print("starting")
  34     print(a.thing)
  35     print(a.thing())
  36     print(a.thing)
  37     print(a.thing())
  38     print(a.thing)
  39     print(b.thing())
  40     print(b.thing())